The present invention relates to reflection type optical scanners that are used for example in laser beam printers. Recently, the demand for more compact laser beam printers and more compact optical scanning devices for use therein has increased. A conventional reflection type optical scanning device is disclosed in Japanese Patent Provisional Publication HEI 6-265810. As disclosed therein, in an optical scanning device, a laser beam is generated at a laser source pointed at a polygonal mirror, reflected back by the polygonal mirror (towards the laser source and angled upwards) to a cylindrical mirror, and reflected back again (towards the polygonal mirror and again angled upward) to a toric lens and optical path bending mirror. The beam is reflected by the optical path bending mirror toward an imaging drum. In this case, "up" is a sub-scanning direction.
However, in the disclosed optical scanning device, the length of the optical path between the light source and polygonal mirror is straight and relatively fixed, making it difficult to reduce the size of the device. Furthermore, the positioning of the remaining optical elements also makes it difficult to produce a compact scanning device using the conventional arrangement.